Exact solution for linear and nonlinear systems of PDEs by Homotopy-Perturbation method.

In this paper, the homotopy-perturbation method (HPM) proposed by J.-H. He is adopted for solving linear and nonlinear systems of partial differential equations (PDEs). In this method, a homotopy parameter p, which takes the values from 0 to 1, is introduced. When p = 0, the system of equations usually reduces to a sufficiently simplified form, which normally admits a rather simple solution. As p gradually increases to 1, the system goes through a sequence of 'deformations', the solution of each of which is 'close' to that at the previous stage of 'deformation'. Eventually at p = 1, the system takes the original form of the equation and the final stage of 'deformation' gives the desired solution. Some examples are presented to demonstrate the efficiency and simplicity of the method

A growth selection system for the directed evolution of amine forming or converting enzymes

Fast screening of enzyme variants is crucial for tailoring biocatalysts for the asymmetric synthesis of non natural chiral chemicals, such as amines. However, most existing screening methods either are limited by the throughput or require specialized equipment. Herein, we report a simple, high throughput, low equipment dependent, and generally applicable growth selection system for engineering amine forming or converting enzymes and apply it to improve biocatalysts belonging to three different enzyme classes. This results in i an amine transaminase variant with 110 fold increased specific activity for the asymmetric synthesis of the chiral amine intermediate of Linagliptin; ii a 270 fold improved monoamine oxidase to prepare the chiral amine intermediate of Cinacalcet by deracemization; and iii an ammonia lyase variant with a 26 fold increased activity in the asymmetric synthesis of a non natural amino acid. Our growth selection system is adaptable to different enzyme classes, varying levels of enzyme activities, and thus a flexible tool for various stages of an engineering campaig

Original Article Randomized Controlled Trial of Mindfulness-Based Therapy for Dyspnea in Chronic Obstructive Lung Disease

Abstract Objectives: Patients with chronic obstructive lung disease (COPD) suffer from significant dyspnea and may benefit from complementary and alternative medicine (CAM) therapies aimed at mitigating symptoms. The objective of this study was to test the efficacy of a mindfulness-based breathing therapy (MBBT) on improving symptoms and health-related quality of life in those with COPD. Design: We conducted a randomized controlled trial of 8-week mindfulness-based breathing therapy (MBBT) compared to support groups to test efficacy on improving symptoms and health-related quality of life in those with COPD. Setting: The setting for this study was an academic-affiliated veterans healthcare system. Subjects: The subjects consisted of 86 patients with COPD. Interventions: MBBT included weekly meetings practicing mindfulness mediation and relaxation response. Outcome measures: The main outcome measure was a post 6-minute-walk test (6MWT) Borg dyspnea assessment. Other outcome measures included health-related quality of life measures, 6MWT distance, symptom scores, exacerbation rates, and measures of stress and mindfulness. Analysis of covariance compared differences in outcomes between groups; paired t test evaluated changes within groups. Results: Participants were predominantly elderly men with moderate to severe COPD. We found no improvements in dyspnea (post 6MWT Borg difference between the MBBT and support group was 0.3 (95% confidence interval [CI]: À

Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo